Cyanohydrin of which compound on hydrolysis will give lactic acid?

$A$ compound of molecular formula $C_8H_8O_2$ reacts with acetophenone to form a single cross-aldol product in the presence of base. The same compound on reaction with conc. $NaOH$ forms benzyl alcohol as one of the products. The structure of the compound is

$CH_3-CO-CH_3 + [O] \xrightarrow{SeO_2} P + Se + H_2O$. What is $P$ here?

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$ : $Image-I$ can be easily reduced using $Zn-Hg / HCl$ to $Image-II$.
Reason $R : Zn-Hg / HCl$ is used to reduce carbonyl group to $-CH_2-$ group.
In the light of the above statements,choose the correct answer from the options given below:

Which among the following compounds has the highest boiling point?

Consider the above reaction,the major product $'P'$ is:-